Abstract
Iodine was adsorbed on silver (111) at room temperature forming a (√3×√3)-30° structure. Thermal desorption experiments, mass analysis and measurements of the change in work function were carried out in addition to LEED to get a realistic adsorption model: The iodine was found to be adsorbed atomically with one atom per unit mesh. The position of the iodine atom within the unit mesh must be deduced from the LEED theory using experimental intensity data. For this purpose intensity-versus-energy curves of several diffraction spots were obtained by means of a spot photometer.